Dust collector

ABSTRACT

A dust collector in one aspect of the present invention comprises a dust collection portion, a communication portion, and an interlock operation control portion. When the communication portion receives an interlock command transmitted from an electric working machine, the interlock operation control portion makes the dust collection portion operate interlocking with the electric working machine. The interlock operation control portion includes a storage portion, in which identification information specific to the electric working machine with which the dust collection portion is to be made to perform the interlock operation is stored.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Continuation of application Ser. No. 14/906,413 filed Jan. 20,2016, which claims the benefit of Japanese Patent Application No.2013-161506 filed Aug. 2, 2013 in the Japan Patent Office and JapanesePatent Application No. 2013-161507 filed Aug. 2, 2013 in the JapanPatent Office. The entire disclosure of Japanese Patent Application No.2013-161506 and the entire disclosure of Japanese Patent Application No.2013-161507 are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a dust collector that is capable ofperforming an interlock operation with an electric working machine.

BACKGROUND ART

A dust collector in one example comprises a communication unit (adapter)that receives a signal wirelessly transmitted from an electric workingmachine during operation of the electric working machine; the dustcollector is configured to be operated when the communication unitreceives the signal from the electric working machine (see, for example,Patent Document 1).

This dust collector can be operated interlocking with the electricworking machine, without providing a signal line for detecting anoperation state of the electric working machine between the dustcollector and the electric working machine. Accordingly, this dustcollector enables an interlock operation with the electric workingmachine even if, for example, the electric working machine is achargeable cordless device.

PRIOR ART DOCUMENTS Patent Documents

-   Patent Document 1: Japanese Patent No. 4955332

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, the dust collector in the above-described example starts theinterlock operation upon receipt of the single transmitted from theelectric working machine. For this reason, if multiple electric workingmachines that transmit signals for an interlock operation are presentaround the dust collector, the dust collector may be operated, contraryto the user's intention, by a signal from an electric working machinethat does not require an interlock operation with the dust collector.

In one aspect of the present invention, it is desirable to provide thefollowing dust collector: even if multiple electric working machines arepresent around the dust collector, the dust collector can perform aninterlock operation only when the dust collector receives a signal froman electric working machine that requires the interlock operation.

Means for Solving the Problems

A dust collector in one aspect of the present invention comprises a dustcollection portion, a communication portion, and an interlock operationcontrol portion. The dust collection portion sucks dust through a dustcollection hose. The communication portion wirelessly communicates withan electric working machine. The interlock operation control portionmakes the dust collection portion perform an interlock operation withthe electric working machine when the communication portion receives aninterlock command transmitted from the electric working machine. Theinterlock operation control portion comprises a storage portion in whichidentification information is stored, and the identification informationis specific to the electric working machine with which the dustcollection portion is to be made to perform the interlock operation.

In the dust collector as configured above, the interlock operationcontrol portion can determine whether the electric working machinetransmitting the interlock command is a device to be interlocked or adevice not to be interlocked.

Here, the interlock command transmitted from the electric workingmachine may include an interlock operation request signal requesting theinterlock operation and an identification signal indicating theidentification information.

In this case, based on the interlock operation request signal and theidentification signal, the interlock operation control portion candetermine that the interlock command has been transmitted from theelectric working machine that requires the interlock operation, so as tomake the dust collection portion perform the interlock operation. Inaddition, a timing of start of the interlock operation by the dustcollection portion can be set based on the transmission of the interlockoperation request signal from the electric working machine; thus, thedust collection portion can be operated properly.

The interlock operation control portion may be further configured suchthat when the identification information obtained from theidentification signal received by the communication portion coincideswith the identification information stored in the storage portion andthe interlock operation request signal is received by the communicationportion, the interlock operation control portion makes the dustcollection portion perform the interlock operation.

In this case, the interlock operation control portion correctlyrecognizes that the signal received by the communication portion is thesignal from the electric working machine to be interlocked, and theinterlock operation can be started by the interlock operation requestsignal; this can further reduce possibility in which the dust collectionportion is erroneously operated.

It may be configured such that while the communication portion receivesthe interlock command periodically and repeatedly transmitted by theelectric working machine during operation of the electric workingmachine, the interlock operation control portion makes the dustcollection portion perform the interlock operation.

Also, when the communication portion has not received the interlockcommand for a specified period of time or more, the interlock operationcontrol portion may stop the interlock operation of the dust collectionportion. In this case, if the interlock operation of the dust collectionportion becomes unnecessary, for example, if the electric workingmachine stops operating or moves far away, it is possible to stop theoperation of the dust collection portion.

Accordingly, compared with a configuration in which the electric workingmachine transmits, as the interlock command, a signal instructing tostart and stop the interlock operation and the dust collector controlsthe start and stop of the interlock operation in accordance with thesignal, the operation of the dust collection portion can be reliablystopped.

Moreover, the specified period of time before the control portion stopsoperation of the dust collection portion may be set to be longer than atransmission cycle in which the electric working machine periodicallytransmits the interlock command.

In this case, it can be more reliably determined that the electricworking machine stops the interlock command, thereby to stop theoperation of the dust collection portion; consequently, it is possibleto suppress or inhibit that the operation of the dust collection portionis erroneously stopped.

The dust collector may further comprise a registration operation portionconfigured to input a command for additionally registering theidentification information specific to the electric working machine withwhich the dust collection portion is to be made to perform the interlockoperation. Also, the interlock operation control portion mayadditionally register the identification information in the storageportion in accordance with the command from the registration operationportion.

In this case, the electric working machine as an object of the interlockoperation can be registered by the dust collector alone and thus,usability of the dust collector can be improved. Moreover, it is notnecessary to provide an operation portion for registration of theidentification information in the electric working machine. Thus, theelectric working machine can be downsized.

Furthermore, when receiving the command for additionally register theidentification information from the registration operation portion, theinterlock operation control portion may transmit an identificationinformation transmission request to a nearby electric working machinevia the communication portion; and after the transmission, the interlockoperation control portion may additionally register the identificationinformation received by the communication portion in the storageportion.

In this case, when a user of the dust collector operates theregistration operation portion to register, in the storage portion, theidentification information of the electric working machine to beinterlocked, it is not necessary to input such identificationinformation by operating the operation portion; thus, registrationoperation of the identification information to the storage portion canbe simplified.

Moreover, since the identification information to be registered in thestorage portion is transmitted from the electric working machine, it ispossible to suppress or inhibit registration of wrong identificationinformation in the storage portion; therefore, the identificationinformation can be correctly registered.

A receivable distance at which the electric working machine can receivea signal transmitted from the communication portion may be set to beshorter than a receivable distance at which the communication portioncan receive a signal transmitted from the electric working machine.

If the receivable distance is set as describe above, the identificationinformation transmission request can be selectively transmitted to theelectric working machine(s) located in the vicinity of the dustcollector; this can reduce possibility of erroneous registration ofidentification information of an electric working machine that does notrequire the interlock operation of the dust collection portion.

Here, to set the receivable distance as described above, for example,transmission power from the communication portion and receivingsensitivity in the communication portion, or transmission power andreceiving sensitivity of the electric working machine, etc. may beadjusted.

Furthermore, after the interlock operation control portion transmits theidentification information transmission request to the nearby electricworking machine via the communication portion, when the communicationportion receives a plurality of pieces of identification information,the interlock operation control portion may suspend the additionalregistration of the identification information in the storage portionand notify the suspension via a notification portion.

In this case, possibility of erroneous registration of identificationinformation of an electric working machine that does not require theinterlock operation of the dust collection portion can be reduced. Inaddition, failure of additional registration of the identificationinformation is notified; the user can dispose an electric workingmachine, the identification information of which is desired to beregistered, in the vicinity of the dust collector but dispose otherelectric working machines away from the dust collector, thereby allowingthe user to try the registration again. Therefore, it is possible toimprove working efficiency in the registration of the identificationinformation.

Furthermore, when the identification information is additionallyregistered in the storage portion, the interlock operation controlportion may notify the additional registration via the notificationportion.

In this case, the user can recognize that additional registration of anew electric working machine, which becomes an object of the interlockoperation, is succeeded with respect to the dust collector andtherefore, improved working efficiency in the registration of theidentification information can be achieved.

Furthermore, when the communication portion receives a registrationrequest of the identification information transmitted from the electricworking machine, the interlock operation control portion mayadditionally register the identification information in the storageportion.

In this case, although the electric working machine needs to be providedwith an operation portion for transmitting the registration request ofthe identification information, the identification information can beadditionally registered to the storage portion in accordance with therequest from the electric working machine. Consequently, improvedworking efficiency in the registration of the identification informationcan be achieved.

In this case, furthermore, after the communication portion receives theregistration request of the identification information, the interlockoperation control portion may notify, via the notification portion,whether the identification information is additionally registered in thestorage portion.

The dust collector may further comprise a deletion operation portionthat inputs a command for deleting the identification information storedin the storage portion. Moreover, the interlock operation controlportion may delete the identification information stored in the storageportion in accordance with the command from the deletion operationportion.

In this case, the identification information of the electric workingmachine to be interlocked, which is registered in the control portion,can be deleted by operating the deletion operation portion. Accordingly,it is possible to easily change an electric working machine thatperforms the interlock operation of the dust collector.

In addition, because unnecessary registration of the identificationinformation in the storage portion can be deleted, a storage capacity ofthe storage portion can be reduced.

Furthermore, when a command for deleting the identification informationis inputted from the deletion operation portion while the interlockoperation control portion makes the dust collection portion perform theinterlock operation, the interlock operation control portion may delete,from the storage portion, the identification information used to makethe dust collection portion perform the interlock operation.

In this case, it is possible to delete, from the storage portion, theidentification number of the electric working machine with which thedust collector is currently made to perform the interlock operation;thus, the identification number of the electric working machine, whichis to be deleted, can be easily and correctly specified.

The dust collector may comprise a dust collector main body and acommunication unit. The dust collector main body may comprise at leastthe dust collection portion and may operate by receiving a power supplyfrom an external alternating current power source. The communicationunit may comprise at least the communication portion; the communicationunit may be attached to the dust collector main body and may receive theinterlock command wirelessly transmitted from the electric workingmachine to output an operation command to the dust collector main body.

The dust collector main body may comprise an isolation device configuredto electrically isolate the alternating current power source from thecommunication portion.

In this case, even if, by any chance, the user touches an internalcircuit in the communication unit due to misuse of the communicationunit by the user, risk of electrical shock to the user can be suppressedor inhibited.

In addition, the dust collector main body is provided as a separate bodyfrom the communication unit. Accordingly, the dust collector main bodycomprises a terminal for inputting/outputting signals to/from thecommunication unit when the communication unit is attached to the dustcollector main body.

This terminal is electrically isolated from the alternating currentpower source. For this reason, even if the user touches the terminalwhen attaching the communication unit to the dust collector main body,possibility of electrical shock to the user can be reduced or eliminatedand therefore, safety of the dust collector can be improved.

The isolation device may comprise an isolation transformer, and theisolation transformer may be used to take in the alternating currentpower inside the dust collector. In this case, not only because theisolation transformer can isolate between the communication unit and thealternating current power source, but also because electric power can betaken in from the alternating current power source via the isolationtransformer, it is possible to supply electric power to an internalcircuit in the dust collector main body and to the communication unit.

The isolation device may comprise a contactless circuit configured tocontactlessly transmit a signal between an operation portion and thecommunication unit, and the operation portion is configured to operateby receiving a power supply from the alternating current power source.

In this case, it is possible to suppress or inhibit entry of noise fromthe alternating current power source into the communication unit viainput/output of signals.

Moreover, because signals are inputted/outputted contactlessly,possibility of contact failure that occurs between signal input/outputterminals can be reduced or eliminated and therefore, reliability of thedust collector can be enhanced.

The communication unit may comprise an antenna for wirelesscommunication, a signal input/output portion, and a communicationcontrol portion. The signal input/output portion inputs and outputs asignal including the operation command to and from the dust collectormain body. The communication control portion controls signals inputtedand outputted via the antenna and the signal input/output portion.

In this case, the antenna may be disposed on a side opposite to thesignal input/output portion across the communication control portion.

The signal input/output portion is coupled to a circuit inside the dustcollector main body; in many cases, part of the signal input/outputportion is a wall inhibiting wireless communication; moreover, the partmay be located close to an internal circuit of the dust collector mainbody, which is a noise source.

When the antenna is disposed as described above, the antenna can belocated away from the wall inhibiting wireless communication and thenoise source, which enables to improve communication quality of thewireless communication with the electric working machine.

The dust collector main body may comprise a power supply path and adetection circuit. The power supply path supplies an electric power tothe communication unit. The detection circuit detects, based on anelectric current flowing to the power supply path, that thecommunication unit is attached.

In this case, it is possible to detect attachment of the communicationunit without providing, in the dust collector main body, a terminaldedicated to detection of attachment of the communication unit. Thus, asize of a connecter for attaching the communication unit, which isprovided in the dust collector main body, can be reduced, therebyachieving downsize and cost reduction of the dust collector main body.

The communication unit may comprise a case, an antenna for wirelesscommunication, a signal input/output portion, and a communicationcontrol portion. At least the communication control portion may becovered by a waterproof resin member and housed inside the case.

In this case, the communication control portion of the communicationunit is provided with two layers of waterproofing, i.e., with the caseof the communication unit and with the waterproof resin member. Thus,erroneous operation of the control portion of the communication unit canbe more favorably suppressed or inhibited.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a block diagram showing a schematic configuration of a dustcollector in a first embodiment and an internal configuration of anelectric power tool that makes the dust collector perform an interlockoperation.

FIG. 1B is a block diagram showing an internal configuration of the dustcollector.

FIG. 2 is an illustrative view illustrating a transmission signal thatis transmitted from the electric power tool to the dust collector whenthe electric power tool and the dust collector operate interlocking witheach other.

FIG. 3A shows flowcharts of a registration request process and aninterlock operation request process, which are executed in the electricpower tool, and a flowchart of a part of a tool-registration andinterlock-operation control process executed in the dust collector inresponse to the aforementioned request processes.

FIG. 3B is a flowchart of the rest of the tool-registration andinterlock-operation control process.

FIG. 4A shows a flowchart of a part of an identification-numberadditional registration process executed in the dust collector, and aflowchart of an identification-number transmission process executed inthe electric power tool in response to the additional registrationprocess.

FIG. 4B is a flowchart of the rest of the additional registrationprocess.

FIG. 5 is a flowchart of an identification-number deletion processexecuted in the dust collector.

FIG. 6 is a flowchart illustrating a modified example of theidentification-number transmission process shown in FIG. 4A.

FIGS. 7A and 7B are illustrative views each showing a configuration of acommunication unit provided in the dust collector.

FIGS. 8A and 8B are illustrative views each showing a configuration of acommunication unit provided in the electric power tool.

EXPLANATION OF REFERENCE NUMERALS

2 . . . electric power tool, 4 . . . dust collector, 10 . . . tool mainbody, 12 . . . cutting grindstone, 14 . . . motor, 16 . . . drivecircuit, 18 . . . trigger switch, 20 . . . battery pack, 22 . . .battery, 30 . . . communication unit, 32 . . . operation detectioncircuit, 33 . . . antenna, 34 . . . transmission and reception circuit,36 . . . control circuit, 37 . . . identification-number settingportion, 38 . . . SW circuit, 40 . . . dust-collector main body, 41 . .. dust collection hose, 42 . . . dust collection motor, 44 . . . dustcollection motor driving circuit, 45 . . . power plug, 46 . . .changeover SW, 48 . . . signal isolation circuit, 50 . . . controlcircuit, 52 . . . isolated control power source, 52 . . . controlcircuit, 53 . . . power outlet, 54, 56 . . . current detection circuit,58 . . . IF circuit, 60 . . . communication unit, 61 . . . antenna, 62 .. . transmission and reception circuit, 64 . . . control circuit, 66 . .. IF circuit, 68 . . . memory, 70 . . . SW circuit, 72 . . .notification circuit, 80, 90 . . . circuit board, 82 . . . componentmounting area, 84, 92 . . . resin case, 86, 94 . . . outer case, 95, 96. . . attachment portion.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, exemplified embodiments of the present invention will bedescribed with reference to the drawings.

First Embodiment

As shown in FIG. 1A, a dust collector 4 of the first embodimentcomprises a dust collection hose 41, a tip end of which is disposed inthe vicinity of an electric power tool 2. The dust collector 4 isconfigured to suck, through the dust collection hose 41, dust includingpowder dust or cutting chips discharged from the electric power tool 2.Also, the dust collector 4 comprises a dust-collector main body 40 and acommunication unit 60.

The electric power tool 2 is a grinder that cuts a workpiece to beprocessed, by rotating a cutting grindstone 12 by a motor 14. Theelectric power tool 2 comprises a tool main body 10, a battery pack 20that supplies electric power to the tool main body 10, and acommunication unit 30 provided between the tool main body 10 and thebattery pack 20.

The tool main body 10 comprises the motor 14, a power transmitter (notshown) that transmits rotation of the motor 14 to the cutting grindstone12, a drive circuit 16 that drives the motor 14 upon receipt of powersupply from the battery pack 20, and a trigger switch 18 that isoperated by a user to input a drive command for the motor 14.

The communication unit 30 comprises an operation detection circuit 32that detects a drive state of the motor 14, a transmission and receptioncircuit 34 that wirelessly communicates with the communication unit 60in the dust collector 4 via an antenna 33, and a control circuit 36.

The operation detection circuit 32 is configured to detect the drivestate of the motor 14 based on an electric current flowing through apower supply path from a battery 22 inside the battery pack 20 to thedrive circuit 16.

When the operation detection circuit 32 detects driving of the motor 14(in other words, operation of the tool main body 10), the controlcircuit 36 makes the transmission and reception circuit 34 transmit aninterlock command to the communication unit 60 in the dust collector 4,thereby making the dust collector 4 perform an interlock operation.

Moreover, when transmitting the interlock command to the communicationunit 60 in the dust collector 4, the communication unit 30 periodicallytransmits a signal (interlock command), which include an interlockoperation request signal and an identification number signal, at aspecified time interval, as shown in FIG. 2. The interlock operationrequest signal is a signal having a specified bit length. Theidentification number signal is a signal having a specified bit lengthindicating an identification number (for example, product serial number)of the communication unit 30.

For this reason, the communication unit 30 comprises anidentification-number setting portion 37 in which an identificationnumber of the communication unit 30 itself has been set beforehand.

Upon detection of the operation of the tool main body 10 by theoperation detection circuit 32, the control circuit 36 reads out theidentification number from the identification-number setting portion 37;then, the control circuit 36 periodically outputs, to the transmissionand reception circuit 34, the read identification number asidentification information specific to the electric power tool 2,together with the interlock operation request signal. The controlcircuit 36 of the first embodiment is configured as a microcomputer.However, the control circuit 36 may be configured by combining separatevarious electronic parts; alternatively, the control circuit 36 may bean ASIC (Application Specified Integrated Circuit), a programmable logicdevice, such as FPGA (Field Programmable Gate Array), etc., or anycombination thereof.

Consequently, while the tool main body 10 is operating, the interlockcommand shown in FIG. 2 is periodically transmitted from thecommunication unit 30 to the communication unit 60 in the dust collector4 (see, an interlock operation request process shown in FIG. 3).

Moreover, the communication unit 30 comprises an SW circuit 38 providedwith an operation SW (SW is abbreviation of “switch”); the operation SWis used to input a command (registration command) for registering, inthe dust collector 4, the identification number of the communicationunit 30 itself as the identification information specific to theelectric power tool 2.

When an identification-number registration command is inputted from theSW circuit 38 when the operation of the electric power tool 2 isstopped, the control circuit 36 reads out the identification number fromthe identification-number setting portion 37 and outputs, to thetransmission and reception circuit 34, an identification-numberregistration signal including an identification-number registrationrequest signal and the identification number signal, therebytransmitting an identification-number registration request from thecommunication unit 30 to the communication unit 60 in the dust-collectormain body 40 (see, a registration request process shown in FIG. 3).

Next, the dust-collector main body 40 comprises a dust collection motor42 for sucking dust including powder dust or cutting chips dischargedfrom the electric power tool 2, a dust collection motor driving circuit44 that drives the dust collection motor 42, and a power plug 45 that isinserted into an external power outlet to receive power supply from analternating-current power source so as to supply the received power tothe dust collection motor driving circuit 44.

Provided on an alternating current power transmission path extendingfrom the power plug 45 to the dust collection motor driving circuit 44is a changeover SW 46; the changeover SW 46 is to be changed among threestates: making the dust collector 4 operate interlocking with theoperation of the electric power tool 2; inhibiting the interlockoperation (i.e., making “Uninterlock”); and stopping the operation ofthe dust collector 4 (i.e., turning “OFF”).

If the changeover SW 46 is not in an OFF state (i.e., “Interlock” or“Uninterlock”), an alternating current voltage inputted from the powerplug 45 is outputted to the dust collection motor driving circuit 44.

Moreover, the dust-collector main body 40 comprises: a control circuit50 that controls driving of the dust collection motor 42 by the dustcollection motor driving circuit 44; an isolated control power source 52that generates a direct-current power supply voltage to be supplied tothe control circuit 50 and to the communication unit 60 attached to thedust-collector main body 40; and a power outlet 53 that supplies analternating current power to an external device. Although the controlcircuit 50 of the first embodiment is configured as a microcomputer, thecontrol circuit 50 may be configured by combining separate variouselectronic parts; alternatively, the control circuit 50 may be an ASIC,a programmable logic device, such as FPGA, or any combination thereof.

When the changeover SW 46 has been changed to “Interlock” or“Uninterlock”, the alternating current power inputted from the powerplug 45 is also supplied to the isolated control power source 52 and thepower outlet 53 via the changeover switch 46.

Provided on an alternating current power supply path extending from thechangeover SW 46 to the power outlet 53 is a current detection circuit54 that detects an alternating current to be supplied to the externaldevice via the power outlet 53.

Moreover, the dust-collector main body 40 comprises an interface circuit(IF circuit) 58; the IF circuit 58 is configured to supply, as a powersource voltage, the direct current voltage generated by the isolatedcontrol power source 52 to the communication unit 60; also, the IFcircuit 58 is configured to transmit/receive, to/from the communicationunit 60, the interlock command transmitted from the communication unit30 in the electric power tool 2 and information such as a drive state ofthe dust collection motor 42, etc.

Provided on a direct-current power supply path extending from theisolated control power source 52 to the IF circuit 58 is a currentdetection circuit 56 that detects a direct current to be supplied to thecommunication unit 60. From this current detection circuit 56, detectionresults of the direct current are inputted to the control circuit 50.

Moreover, results of current detection by the current detection circuit54 and a changeover state of the changeover SW 46 are inputted to thecontrol circuit 50 via a signal isolation circuit 48 comprising aphotocoupler.

The control circuit 50 drives the dust collection motor 42 via the dustcollection motor driving circuit 44, based on the changeover state ofthe changeover SW 46 (in this case, “Interlock” or “Uninterlock”) aswell as a current value of the alternating current supplied from thepower outlet 53 to the external device.

Also, the control circuit 50 determines whether the communication unit60 is attached to the IF circuit 58 based on a current value of thedirect current detected by the current detection circuit 56. If thecommunication unit 60 is attached and the changeover SW 46 has beenchanged to “Interlock”, the control circuit 50 drives the dustcollection motor 42 via the dust collection motor driving circuit 44 inaccordance with a drive command inputted from the communication unit 60.

Moreover, a control signal, which is outputted from the control circuit50 to the dust collection motor driving circuit 44, is also inputted tothe dust collection motor driving circuit 44 via the signal isolationcircuit 48 comprising the photocoupler.

This is because, by means of the signal isolation circuit 48 and theisolated control power source 52, the communication unit 60 to becoupled to the IF circuit 58 is made to be electrically isolated from apath of the alternating current voltage supplied from the externalalternating-current power source via the power plug 45.

That is to say, in the first embodiment, the signal isolation circuit 48and the isolated control power source 52 allow the internal circuits inthe dust-collector main body 40, which receive power supply from theexternal alternating-current power source, to supply electric power tothe communication unit 60 or to transmit/receive signals to/from thecommunication unit 60 while the internal circuits are being isolatedfrom the alternating-current power source. With this configuration, riskof electrical shock to the user when the user touches the IF circuit 58is to be suppressed or inhibited.

Moreover, the isolated control power source 52 includes an isolationtransformer; the isolation transformer receives power supply from thealternating-current power source by dropping the alternating currentvoltage. Alternatively, an isolating switching power source may be usedas the isolated control power source 52 so as to supply a constantvoltage direct-current power to the control circuit 50.

Next, the communication unit 60 comprises an IF circuit 66 thatcomprises a terminal portion attachable to the IF circuit 58 in thedust-collector main body 40, a transmission and reception circuit 62that wirelessly communicates with the communication unit 30 in theelectric power tool 2 via an antenna 61, and a control circuit 64 thatis provided between the transmission and reception circuit and the IFcircuit 66.

The control circuit 64 is configured to control transmission/receptionsignals by the transmission and reception circuit 62 and input/outputsignals by the IF circuit 66.

Specifically, when the transmission and reception circuit 62 receivesthe interlock operation request signal transmitted from thecommunication unit 30 of the electric power tool 2, the control circuit64 determines, based on the identification number signal transmittedtogether with the interlock operation request signal, whether theelectric power tool 2 is an electric power tool as an object of theinterlock operation.

If the electric power tool 2 is to be interlocked, the drive command ofthe dust collection motor 42 is outputted to the control circuit 50 inthe dust-collector main body 40 to make the dust collection motor 42perform the interlock operation.

To enable this, the communication unit 60 comprises a non-volatilememory (hereinafter, simply referred to as a memory) 68 for storing anidentification number of the electric power tool as the object of theinterlock operation.

When the transmission and reception circuit 62 receives theidentification number transmitted from the electric power tool 2, thecontrol circuit 64 determines whether this identification numbercoincides with the identification number in the memory 68; if theseidentification numbers coincide, the control circuit 64 makes the dustcollection motor 42 perform the interlock operation (see, atool-registration and interlock-operation control process shown in FIG.3). Here, the control circuit 64 in the first embodiment is configuredas a microcomputer. However, the control circuit 64 may be configured bycombining separate various electronic parts; alternatively, the controlcircuit 64 may be an ASIC, a programmable logic device, such as FPGA,etc., or any combination thereof.

Moreover, the memory 68 for storing the identification number comprises,for example, an EEPROM, a flash memory, or the like, which is capable ofadditionally registering the identification number and deleting theidentification number.

Furthermore, when the identification-number registration request istransmitted to the control circuit 64 from the communication unit 30 inthe electric power tool 2, the control circuit 64 additionally registersin the memory 68 the identification number included in this registrationrequest (see the tool-registration and interlock-operation controlprocess shown in FIG. 3).

Moreover, the communication unit 60 comprises a SW circuit 70 and anotification circuit 72; the SW circuit 70 comprises a registration SWfor instructing additional registration of the identification number inthe memory 68 and a deletion SW for instructing deletion of theidentification number registered in the memory 68; the notificationcircuit 72 is to notify registration results and deletion results of theidentification number in the memory 68.

When an additional registration command of the identification number isinputted from the registration SW inside the SW circuit 70, the controlcircuit 64 executes an additional registration process (see FIG. 4) toobtain the identification number from the electric power tool 2 locatedaround the dust collector 4 and register the identification number inthe memory 68. Meanwhile, when a deletion command of the identificationnumber is inputted from the deletion SW inside the SW circuit 70, thecontrol circuit 64 executes an identification-number deletion process(see FIG. 5) to delete the identification number from the memory 68.

Next, referring to FIGS. 3A and 3B, the registration request process andthe interlock operation request process, which are executed in thecontrol circuit 36 inside the communication unit 30 of the electricpower tool 2, and the tool-registration and interlock-operation controlprocess, which is executed in the control circuit 64 inside thecommunication unit 60 of the dust collector 4, will be described.

As shown in FIGS. 3A and 3B, the registration request process is aprocess to be executed as one of main routines in the control circuit 36when the motor 14 in the electric power tool 2 is stopped. Upon start ofthis process, in S110 (S represents a step), it is determined whetherthe identification-number registration command has been inputted fromthe SW circuit 38.

If the identification-number registration command has not been inputted,S110 is executed again to wait for the registration command to beinputted. However, if it is determined in S110 that theidentification-number registration command has been inputted from the SWcircuit 38, the process proceeds to S120.

In S120, the above-described signal including the identification-numberregistration request signal and the identification number signal isoutputted to the transmission and reception circuit 34, therebytransmitting the identification-number registration request from thecommunication unit 30. After the identification-number registrationrequest is transmitted in S120, the process returns to S110.

Next, the interlock operation request process is a process to beexecuted as one of main routines in the control circuit 36 when thetrigger switch 18 is operated to drive the motor 14. Upon start of thisprocess, in S130, it is determined whether a tool current (electriccurrent flowing to the motor 14 via the drive circuit 16), which isdetected by the operation detection circuit 32, has exceeded a thresholdvalue pre-set for determining operations of the electric power tool 2.

If the tool current does not exceed the threshold value, S130 isexecuted again to wait until the tool current exceeds the thresholdvalue (i.e., wait until the electric power tool 2 starts a normalprocessing operation). If the tool current exceeds the threshold value,the process proceeds to S140.

In S140, the interlock command shown in FIG. 2 is outputted to thetransmission and reception circuit 34, thereby transmitting theinterlock command from the communication unit 30.

In the subsequent S150, after the transmission of the interlock command,the process waits until a specified time T1 has passed. When thespecified time T1 has passed, the process returns to S130.

As a result, in the interlock operation request process, when the toolcurrent exceeds the threshold value (i.e., while the electric power tool2 is operating), an interlock operation request is to be periodicallyand repeatedly transmitted at the following time interval; the timeinterval is obtained by adding the specified time T1 to a transmissiontime necessary to output the interlock command to the transmission andreception circuit 34, the interlock command including the interlockoperation request signal and the identification number signal.

Next, the tool-registration and interlock-operation control process is aprocess to be repeatedly executed as one of main routines in the controlcircuit 64. Upon start of this process, in S210, it is determinedwhether the identification-number registration request has been receivedin the transmission and reception circuit 62.

Then, if the identification-number registration request has beenreceived in the transmission and reception circuit 62, the processproceeds to S220 to determine whether the identification numbertransmitted from the electric power tool 2 side has been received in thetransmission and reception circuit 62.

In S220, if it is determined that the identification number has beenreceived, the process proceeds to S230 to store (additionally register)the received identification number in the memory 68. In the subsequentS240, completion of storing the identification number is notified (forexample, by lighting a success indication lamp comprising an LED, etc.)via the notification circuit 72 and then, the process returns to S210.

However, if it is determined in S220 that the identification number hasnot been received, in S250, failure of storing the identification numberis notified (for example, by lighting an error indication lampcomprising an LED, etc.) via the notification circuit 72 and then, theprocess returns to S210.

On the other hand, in S210, if it is determined that theidentification-number registration request has not been received, theprocess proceeds to S260 to determine whether the interlock operationrequest has been received in the transmission and reception circuit 62.

If the interlock operation request has been received in the transmissionand reception circuit 62, the process proceeds to in S270 to determinewhether the identification number transmitted from the electric powertool 2 side has been received in the transmission and reception circuit62.

If it is determined in S270 that the identification number has beenreceived, the process proceeds to S280 to determine whether the receivedidentification number is stored (registered) in the memory 68, therebydetermining whether the electric power tool 2 that transmitted theinterlock operation request is an electric power tool that is an objectof the interlock operation.

Then, in S280, if it is determined that the received identificationnumber this time is stored (registered) in the memory 68, the electricpower tool that transmitted the identification number is confirmed asthe object of the interlock operation; thus, the process proceeds toS290.

In S290, the control circuit 50 in the dust-collector main body 40 isinstructed to drive the dust collection motor 42 via the IF circuits 66and 58, thereby making the dust collection motor 42 (and therefore, thedust collector 4) perform the interlock operation.

After the process in S290 is performed, in S300, the process waits untila specified time T2 has passed. When the specified time T2 has passed,the process returns to S210.

In this regard, the specified time T2 is a time for executing a seriesof processes S210 to S290 in a time period that is longer than atransmission cycle in which the communication unit 30 in the electricpower tool 2 periodically transmits the interlock operation request bythe interlock operation request process.

For this reason, the specified time T2 is set to be longer than thespecified time T1 during which the process waits in S150 of theinterlock operation request process.

However, when negative determination is made in any of S260, S270, andS280, i.e., when the interlock operation is not requested from theelectric power tool, when the identification number cannot be receivedproperly, or when the received identification number is not from theelectric power tool as the object of the interlock operation, theprocess proceeds to S310.

In S310, a stop command of the dust collection motor 42 is outputted tothe control circuit 50 of the dust-collector main body 40 via the IFcircuits 66 and 58, thereby stopping driving of the dust collectionmotor 42; then, the process returns to S210.

Next, with reference to FIGS. 4A and 4B, an identification-numberadditional registration process and an identification-numbertransmission process will be explained; the identification-numberadditional registration process is executed in the control circuit 64when the additional registration command of the identification number isinputted from the registration SW inside the SW circuit 70 provided inthe communication unit 60 of the dust collector 4; and in conjunctionwith the identification-number additional registration process, theidentification-number transmission process is executed in the controlcircuit 36 inside the communication unit 30 of the electric power tool2.

The additional registration process is a process to be executed as oneof main routines in the control circuit 64, together with theabove-described tool-registration and interlock-operation controlprocess. Upon start of the additional registration process, in S410, itis determined whether the registration SW inside the SW circuit 38 is inan ON state.

If the registration SW is not in the ON state, S410 is executed again towait for the registration SW to be changed to the ON state. When it isdetermined in S410 that the registration SW is in the ON state, theprocess proceeds to S420.

In S420, an identification-number transmission request is outputted tothe transmission and reception circuit 62, thereby making thetransmission and reception circuit 62 transmit a transmission requestfor the identification number to the electric power tool 2 locatedaround the dust collector 4.

On the other hand, in the communication unit 30 provided in the electricpower tool 2, the control circuit 36 is configured to execute theidentification-number transmission process shown in FIG. 4A as one ofmain routines.

In this identification-number transmission process, in S510, it isdetermined whether the transmission and reception circuit 62 hasreceived the identification-number transmission request transmitted fromthe communication unit 60 in the dust collector 4, thereby waiting forthe identification-number transmission request to be received in thetransmission and reception circuit 62.

If it is determined in S510 that the identification-number transmissionrequest has been received in the transmission and reception circuit 62,the process proceeds to S520; in S520, from the identification-numbersetting portion 37, the identification number of itself is read out andthen outputted to the transmission and reception circuit 34, so as tomake the transmission and reception circuit 34 transmit theidentification number; then, the present identification-numbertransmission process is terminated.

Here, after the termination, the identification-number transmissionprocess is restarted after a specified waiting time has elapsed, and isexecuted in the same manner as described above.

For this reason, in the additional registration process in the dustcollector 4 side, in S420, the transmission request of theidentification number is transmitted from the transmission and receptioncircuit 62; thereafter, in S430, the identification number istransmitted from the nearby electric power tool 2 and then, it isdetermined whether a prescribed time necessary for the transmission andreception circuit 62 to receive this identification number has passed.

When the prescribed time has not yet been passed, it is determined inS440 whether the identification number has been received. If theidentification number has been received, in S450, a number of theidentification numbers received before the prescribed time has passed(“Received Number”) is counted and then, the process returns to S430.Also, if it is determined in S440 that the identification number has notyet been received, the process proceeds to S430.

Here, a transmission power of the transmission and reception circuit 62is set to be low, compared with the transmission and reception circuit34 inside the communication unit 30 provided in the electric power tool2.

This is because, a receivable distance at which the electric power tool2 is capable of receiving the transmission request of the identificationnumber is made to be shorter than a receivable distance at which thecommunication unit 60 of the dust collector 4 can properly receive anelectric wave transmitted from the transmission and reception circuitinside the communication unit 30.

Specifically, a transmission power from the communication unit 30 in theelectric power tool 2 is set to correspond to a length of the dustcollection hose 41 (for example, 5 to 10 m), so that even if the dustcollection hose 41 is fully extended, the communication unit 60 in thedust collector 4 can receive an electric wave transmitted from theelectric power tool 2 in relation to which the tip end of the dustcollection hose 41 is disposed.

On the other hand, a transmission power from the communication unit 60in the dust collector 4 is set such that the receivable distance atwhich the electric power tool 2 side is capable of receiving issufficiently shorter (for example, about 1 m) than the length of thedust collection hose 41.

As a result, when the user operates the registration SW to store(register) the identification number of the electric power tool 2 in thememory 68, the electric power tool 2 to be registered is made close tothe dust collector 4, thereby allowing an electric wave transmitted fromthe communication unit 60 of the dust collector 4 to reach the electricpower tool 2 to be registered, while making it difficult for thiselectric wave to reach an electric power tool 2 that does not requirethe interlock operation with the dust collector 4.

Next, in S430, if it is determined that the prescribed time has passed,the process proceeds to S460 to determine whether the Received Number ofthe identification number counted in S450 is “1”. If “Received Number=1”is satisfied, the process proceeds to S470 to store (additionallyregister) the received identification number in the memory 68.

In the subsequent S480, as in the above-described S240, completion ofstoring the identification number is notified via the notificationcircuit 72 and then, the present additional registration process isterminated.

However, if it is determined in S460 that the Received Number of theidentification number is not “1”, i.e., if the identification numbercannot be received or if a plurality of the identification numbers arereceived, the process proceeds to S490 to notify, as in theabove-described S250, failure of storing the identification number viathe notification circuit 72 and then, the present additionalregistration process is terminated.

Here, after the termination, the additional registration process isrestarted after a specified waiting time has elapsed, and is executed inthe same manner as described above.

Next, the identification-number deletion process will be explained withreference to FIG. 5; the identification-number deletion process isexecuted in the control circuit 64 when the deletion command of theidentification number is inputted from the deletion SW inside the SWcircuit 70 provided in the communication unit 60 of the dust collector4.

The identification-number deletion process is a process to be executedas one of main routines in the control circuit 64, together with theabove-described tool-registration and interlock-operation controlprocess and the additional registration process. Upon start of theidentification-number deletion process, in S610, it is determinedwhether the deletion SW inside the SW circuit 38 is in an ON state.

If the deletion SW is not in the ON state, S610 is executed again towait for the registration SW to become the ON state. If it is determinedin S610 that the registration SW is in the ON state, the processproceeds to S620.

In S620, it is determined whether the dust collection motor 42 in thedust-collector main body 40 is currently being driven (i.e., whether thedust collection motor 42 is performing the interlock operation). If thedust collection motor 42 is performing the interlock operation, theprocess proceeds to S630.

In S630, the identification number of the electric power tool 2 withwhich the dust collection motor 42 is currently made to perform theinterlock operation is confirmed, and this identification number isdeleted from the memory 68, thereby erasing the registration of thiselectric power tool 2.

Then in S640, the deletion of the identification number from the memory68 is notified via the notification circuit 72 and then, the presentidentification-number deletion process is terminated.

However, if it is determined in S620 that the dust collection motor 42is not currently made to perform the interlock operation, theidentification number to be deleted from the memory 68 cannot beidentified and thus, failure of deletion of the identification number isnotified via the notification circuit 72; then, the presentidentification-number deletion process is terminated.

Here, after the termination, the identification-number deletion processis restarted after a specified waiting time has elapsed, and is executedin the same manner as described above.

As explained above, in the dust collector 4 of the first embodiment, thecontrol circuit 64 inside the communication unit 60 executes theabove-described tool-registration and interlock-operation controlprocess; accordingly, the dust collector 4 can be made to perform theinterlock operation only when the electric power tool 2 that sent theinterlock operation request is the electric power tool pre-stored in thememory 68 as an object of the interlock operation.

For this reason, even if a plurality of electric power tools thattransmit the interlock operation requests are present around the dustcollector 4, it is possible to suppress or inhibit the dust collector 4from being operated contrary to the user's intention, by the interlockoperation request from the electric power tools.

Moreover, the interlock operation request from the electric power tool 2is made by periodically transmitting the signal including the interlockoperation request signal and the identification signal. Therefore, inthe dust collector 4 side, operation of the dust collection motor 42 canbe started at a timing of receipt of the signal and also, a start timingof the interlock operation can be made to correspond to operation of theelectric power tool 2.

Furthermore, the electric power tool 2 periodically and repeatedlytransmits the interlock operation request. Meanwhile, when the dustcollector 4 cannot receive the interlock operation request, driving ofthe dust collection motor 42 (in other words, the interlock operation ofthe dust collector 4) is stopped.

Accordingly, compared with a case where the electric power tool 2 isconfigured to transmit a signal instructing start and a signalinstructing stop of the interlock operation, the interlock operation ofthe dust collector 4 can be reliably stopped.

That is, in the case where the electric power tool 2 is configured totransmit a signal instructing start and a signal instructing stop of theinterlock operation, if the transmission and reception circuit 62 cannotreceive a stop command from the electric power tool 2 due to change in acommunication condition between the dust collector 4 and the electricpower tool 2, it is impossible to stop the driving of the dustcollection motor 42.

However, according to the dust collector 4 of the first embodiment, itis possible to reliably stop the driving of the dust collection motor 42without causing the aforementioned problem.

Moreover, in the dust collector 4, the identification number of theelectric power tool 2 as an object of the interlock operation can beadditionally registered in accordance with a command from the SW circuit38 provided in the communication unit 30 of the electric power tool 2 orfrom the SW circuit 70 (specifically, the registration SW) provided inthe communication unit 60 of the dust collector 4.

Furthermore, the registration of the identification number of theelectric power tool 2 as an object of the interlock operation can beremoved by a command from the SW circuit 70 (specifically, the deletionSW) provided in the communication unit 60 of the dust collector 4.

Accordingly, the user can arbitrarily set, in the dust collector 4, theelectric power tool 2 as an object of the interlock operation and also,the setting operation can be easily made by operating a switch in theelectric power tool 2 side or the dust collector 4 side.

Moreover, whether or not this operation of the switch can propertyregister or delete the identification information is notified (in thefirst embodiment, displayed by lighting an LED, etc.) via thenotification circuit 72 provided in the communication unit 60 of thedust collector 4. Therefore, the user can confirm registration resultsor deletion results of the identification information by confirming thestate of the notification.

Thus, the dust collector 4 of the first embodiment provides excellentusability to the users.

Here, in the first embodiment, the dust collection hose 41 and the dustcollection motor 42 correspond to one example of a dust collectionportion of the present invention; the antenna 61 and the transmissionand reception circuit 62 in the communication unit 60 correspond to oneexample of a communication portion of the present invention; the controlcircuit 64 in the communication unit 60 and the control circuit 50 inthe dust-collector main body 40 correspond to one example of aninterlock operation control portion of the present invention; and thememory 68 in the communication unit 60 corresponds to one example of astorage portion of the present invention.

Moreover, the registration SW in the SW circuit 70 provided in thecommunication unit 60 corresponds to one example of a registrationoperation portion of the present invention; likewise, the deletion SWcorresponds to one example of a deletion operation portion of thepresent invention; and the notification circuit 72 corresponds to oneexample of a notification portion of the present invention.

Second Embodiment

The second embodiment is made by modifying part of respectiveconfigurations of the electric power tool 2 and the dust collector 4 inthe first embodiment. Accordingly, in the following description, thesame configurations as those of the first embodiment are assigned withthe same reference numerals as those used in the first embodiment, andwill not be explained; only different configurations will be explained.

In the communication unit 60 of the second embodiment, the antenna 61,the transmission and reception circuit 62, the control circuit 64, theIF circuit 66, the memory 68, the SW circuit 70, and the notificationcircuit 72 are all formed by a circuit pattern(s) of a circuit board 80shown in FIG. 7A and electronic components mounted on the circuit board80.

As shown in FIG. 7A, the antenna 61 and the IF circuit 66 (specifically,a connector for connection to the dust-collector main body 40) aremounted, respectively, on both ends of the circuit board 80. In thecircuit board 80, a component mounting area 82 is set between theantenna 61 and the IF circuit 66; the component mounting area 82 isprovided for electronic components forming the transmission andreception circuit 62, the control circuit 64, the memory 68, the SWcircuit 70, and the notification circuit 72.

Moreover, a resin case 84 for waterproofing is to be attached to thecircuit board 80 so as to cover the component mounting area 82 on whichrespective electronic components of the aforementioned circuits aremounted.

Moreover, the resin case 84 is configured to cover, in addition to thecomponent mounting area 82, part of the IF circuit 66 excluding aconnection portion to the dust-collector main body 40.

As shown in FIG. 7B, the circuit board 80 with the component mountingarea 82 being covered by the resin case 84 for waterproofing is housedin an outer case 86 made of synthetic resin.

The outer case 86 is formed in a shape allowing the connection portionof the IF circuit 66 to protrude outside therefrom, and via thisconnection portion, the communication unit 60 is coupled to the IFcircuit 58 of the dust-collector main body 40.

In the communication unit 30 of the second embodiment, as in thecommunication unit 60 of the dust collector 4, electronic componentsthat form the operation detection circuit 32, the antenna 33, thetransmission and reception circuit 34, the control circuit 36, the SWcircuit 38, and the identification-number setting portion 37 are mountedon a circuit board 90 shown in FIG. 8A.

As shown in FIG. 8A, the antenna 33 is mounted on an end of the circuitboard 90, and the electronic components excluding the antenna 33 aremounted on a component mounting area in a central part of the circuitboard 90. Moreover, as in the communication unit 60 of the dustcollector 4, the component mounting area is covered by a resin case 92for waterproofing.

The above-described circuit board 90, on which the electronic componentsare mounted and to which the resin case 92 is attached so as to coverthe electronic components excluding the antenna 33, is housed in anouter case 94, as in the communication unit 60 of the dust collector 4.

In order to have a function of coupling the tool main body 10 to thebattery pack 20, as shown in FIG. 8B, the outer case 94 comprises anattachment portion 95 for the tool main body 10, which is formed at aside where a mounting surface for the electronic components exists inthe circuit board 90, and an attachment portion 96 for the battery pack20, which is formed in an opposite side to the mounting surface.

A rear end side of the tool main body 10 is to be attached to theattachment portion 95 in a state where the tip end side of the tool mainbody 10, to which the cutting grindstone 12 is to be attached, isprotruded from an opposite side to the antenna 33. The battery pack 20is to be attached to the attachment portion 96.

As explained above, in the dust collector 4 of the second embodiment,the signal isolation circuit 48 comprising a photocoupler and theisolated control power source 52 comprising an isolation transformer areprovided inside the dust-collector main body 40; with these components,a path of an alternating current voltage supplied from the externalalternating-current power source is electrically isolated from thecommunication unit 60.

For this reason, by supplying electric power and transmitting/receivingsignals to/from the communication unit 60 that is isolated from thealternating-current power source, it becomes possible to eliminate orreduce risk of electrical shock in a case where the user touches aterminal of the IF circuit 58 when attaching the communication unit 60to the dust-collector main body 40; consequently, improved safety can beachieved.

Moreover, in the communication unit 60, the antenna 61 is disposed,across the internal circuits such as the control circuit 64, at anopposite side to the IF circuit 66 that is a signal input/output portionin the communication unit 60 side. For this reason, the antenna 61 canbe disposed away from a connection portion to the dust-collector mainbody 40, which may interfere with the wireless communication; thus, thewireless communication by the antenna 61 can be favorably achieved.

Furthermore, in the communication unit 60, all of the constituentcomponents (electronic components) excluding the antenna 61 and theconnector of the IF circuit 66 are to be covered by the resin case 84for waterproofing on the circuit board 80. Thus, waterproof propertiesof the communication unit 60 can be enhanced.

Moreover, especially, the communication unit 30 of the electric powertool 2 is likely to be splashed with water when the electric power tool2 is used. However, also in the communication unit 30, constituentcomponents (electronic components) excluding the antenna 33 are to becovered by the resin case 92 for waterproofing on the circuit board 90.Thus, waterproof properties can be enhanced, and malfunctions caused bysplashing water to the communication unit 30 can be reduced.

Also, in the dust-collector main body 40, the current detection circuit56 is provided on the path for the direct current power supplied fromthe isolated control power source 52 to the communication unit 60. Thecontrol circuit 50 is configured to detect that the communication unit60 has been attached based on the detected electric current by thecurrent detection circuit 56.

With this configuration, it is possible to detect attachment of thecommunication unit without providing, in the dust-collector main body40, a terminal dedicated to detection of attachment of the communicationunit 60. Thus, a size of a connector constituting the IF circuit 58 canbe reduced, thereby facilitating downsizing and cost reduction of thedust-collector main body 40.

Here, in the present embodiment, the isolated control power source 52and the signal isolation circuit 48 correspond to one example of anisolation device of the present invention; and among these two,especially, the signal isolation circuit 48 corresponds to one exampleof a contactless circuit of the present invention. Moreover, the IFcircuit 66 corresponds to one example of a signal input portion of thepresent invention; and the control circuit 64 corresponds to one exampleof a communication control portion of the present invention.

The exemplified embodiments of the present invention have been describedas above; however, the present invention should not be limited to theabove-described first and second embodiments, but can take various formswithin the scope not departing from the spirit of the present invention.

For example, in the above-described embodiments, the electric workingmachine as an object of the interlock operation with the dust collector4 is a grinder; however, any electric working machine in other forms,such as a circular saw, a plane, etc., which discharges powder dust orcutting chips during the operation.

Moreover, in the above-described embodiments, the dust collector 4comprises the dust-collector main body 40 and the communication unit 60that is separately provided from and is detachably attached to thedust-collector main body 40. However, the dust collector 4 may contain acommunication circuit having the same communication function as that ofthe communication unit 60.

In above-described embodiments, the dust collector 4 is configured to beable to additionally register and delete, in and from the memory 68, theidentification number of the electric power tool 2 as an object of theinterlock operation; however, the dust collector 4 may be configured notto perform part or all of the above-described additional registrationand deletion of the identification number.

For example, according to the dust collector 4 of the above-describedembodiments, the user can operate the registration SW of the SW circuit70 provided in the communication unit 60 to make the control circuit 64execute the additional registration process shown in FIGS. 4A and 4B,thereby additional registering the identification number of the electricpower tool 2.

Therefore, it is not absolutely necessary to provide the SW circuit 38for registration of the identification number in the communication unit30 of the electric power tool 2. In other words, it is not necessary touse the SW circuit 38 to make the control circuit 36 in the electricpower tool 2 execute the registration request process shown in FIG. 3A,thereby making the control circuit 64 of the dust collector 4 registerthe identification number of the electric power tool 2.

As described above, if the SW circuit 38 is not provided in thecommunication unit 30 of the electric power tool 2, downsizing and costreduction of the communication unit 30 can be achieved and therefore,demand for reducing size and weight of the electric power tool 2 can bemet.

Moreover, in the above-described embodiments, the identification number(product serial number, etc.) of the communication unit 30 is stored asthe identification information of the electric power tool 2 in thememory 68 and based on this identification number, it is determinedwhether to make the dust collection motor 42 perform the interlockoperation; however, any identification information that can be used toidentify an electric working machine as an object of the interlockoperation may be stored in the memory 68.

Meanwhile, in the above-described embodiments, the identification-numbertransmission process shown in FIG. 4A, which is executed by the controlcircuit 36 inside the communication unit 30 of the electric power tool2, may be modified as shown in FIG. 6.

Specifically, in the identification-number transmission process shown inFIG. 6, if it is determined in S510 that the identification-numbertransmission request has been received in the transmission and receptioncircuit 62, the process proceeds to S515 to determine whether thetrigger switch 18 is in an ON state.

If the trigger switch 18 is in the ON state, the process proceeds toS520 to transmit the identification number of the communication unit 30from the transmission and reception circuit 34. However, if the triggerswitch 18 is not in the ON state, the current identification-numbertransmission process is terminated without transmitting theidentification number.

If the identification-number transmission process, which is executed inthe control circuit 36 in the electric power tool 2, is modified asdescribed above, it is possible to reduce a number of the electric powertools 2 that send the identification number in response to theidentification-number transmission request transmitted by the additionalregistration process shown in FIGS. 4A and 4B, thereby increasingpossibility for the control circuit 64 to additionally register theidentification number in the memory 68.

Specifically, in the additional registration process shown in FIGS. 4Aand 4B, the identification-number transmission request is transmitted toan area around the dust collector 4 via the transmission and receptioncircuit 62, so that the identification number of the electric power tool2 located in the aforementioned area can be obtained and additionallyregistered in the memory 68. However, if multiple identification numbersare obtained, the identification number to be additionally registeredcannot be identified; therefore, the additional registration to thememory 68 is inhibited.

In this regard, if the identification-number transmission processexecuted in the electric power tool 2 is modified as shown in FIG. 6,the identification number is transmitted on the condition that thetrigger switch 18 is in the ON state. Accordingly, it is possible toreduce possibility for the multiple electric power tools 2 to transmitthe identification numbers, thereby facilitating additional registrationof the identification number in the memory 68.

Moreover, when the user operates the trigger switch 18 of the electricpower tool 2, the identification number of which is desired to beregistered, simultaneously with or immediately after operating theregistration SW of the dust collector 4, the identification number ofthis electric power tool 2 can be additionally registered in the memory68 of the dust collector 4.

Thus, the user can more reliably register a desired electric power tool2 as a tool with which the dust collector 4 is made to perform theinterlock operation. In addition, it is possible to further reducepossibility of erroneous registration of an electric power tool that isnot an object of the interlock operation.

Moreover, in the above-described first and second embodiments, in orderto isolate between the communication unit 60 and the externalalternating-current power source, the isolated control power source 52comprising the isolation transformer and the signal isolation circuit 48comprising the photocoupler are provided in the dust-collector main body40. However, an isolation transformer and a photocoupler may be providedin the IF circuit 58, thereby electrically isolating between thedust-collector main body 40 and the communication unit 60.

In addition, this isolation is sufficient when a leakage current flowingfrom the dust-collector main body 40 to the communication unit 60 islimited to a specified value or below. Thus, for example, a capacitor ora resistor may be provided in the current path so that the current pathhas impedance.

Moreover, as the isolated control power source 52, an isolatingswitching power supply may be used.

Furthermore, in the above-described first and second embodiments, adirect current voltage generated by the isolated control power source 52is supplied, as a power source voltage, to the communication unit 60.However, it is not absolutely necessarily to supply power from thedust-collector main body 40 to the communication unit 60, and thecommunication unit 60 may be configured to contain a battery as adirect-current power source.

In this configuration, by simply providing a photocoupler, etc. betweenthe dust-collector main body 40 and the communication unit 60, it ispossible to isolate between the alternating-current power source and thecommunication unit 60; consequently, a function as an isolation devicecan be very easily obtained.

Furthermore, in the second embodiment, it has been described that in thecommunication units 30 and 60, the antennas 33 and 61 are, respectivelydisposed outside the resin cases 84 and 92; however, the antennas 33 and61 may be housed inside the resin cases 84 and 92, respectively.

The invention claimed is:
 1. A dust collector comprising: a dustcollection portion configured to suck dust through a dust collectionhose; a communication portion configured to wirelessly communicate withan electric working machine; a power plug configured to receive analternating-current power from an alternating-current power source; achangeover switch directly electrically coupled to the power plug,wherein the changeover switch is configured to be changed into a firststate, a second state, and a third state, wherein the changeover switchin the first state makes the dust collection portion operateinterlocking with an operation of the electric working machine, thechangeover switch in the second state inhibits the dust collectionportion from an interlock operation with the operation of the electricworking machine, and the changeover switch in the third state stops anoperation of the dust collection portion; and an interlock operationcontrol portion configured to make the dust collection portion performthe interlock operation with the electric working machine in response toreceipt of an interlock command by the communication portion with thechangeover switch being in the first state, wherein the interlockcommand is periodically transmitted from the electric working machine,wherein the interlock operation control portion includes a storageportion in which identification information is stored, theidentification information being specific to the electric workingmachine with which the dust collection portion is to be made to performthe interlock operation, wherein the interlock command includes aninterlock operation request signal and an identification signal, theinterlock operation request signal requesting the interlock operation,and the identification signal indicating the identification information,and wherein the interlock operation control portion is furtherconfigured such that, the interlock operation control portion makes thedust collection portion perform the interlock operation in response toreceipt of the interlock command by the communication portion duringoperation of the electric working machine, and the interlock operationcontrol portion stops the interlock operation of the dust collectionportion in response to no receipt of the interlock command by thecommunication portion for a specified period of time or more.
 2. Thedust collector according to claim 1, wherein the specified period oftime is set to be longer than a transmission cycle in which the electricworking machine periodically transmits the interlock command.
 3. Thedust collector according to claim 1, wherein: the dust collectionportion includes: a motor; and a motor driving circuit configured todrive the motor; and the dust collector includes a transmission pathextending from the power plug through the changeover switch to the motordriving circuit.
 4. The dust collector according to claim 1, furthercomprising a signal isolation circuit coupled to the changeover switchand the interlock operation control portion, wherein a state of thechangeover switch is inputted to the interlock operation control portionvia the signal isolation circuit.
 5. The dust collector according toclaim 4, wherein the signal isolation circuit includes a photocoupler.6. The dust collector according to claim 1, further comprising a controlpower source configured to receive the alternating-current power fromthe alternating-current power source, the control power source beingconfigured to generate a direct-current voltage, wherein the changeoverswitch is coupled to the control power source.
 7. The dust collectoraccording to claim 6, wherein the control power source is electricallycoupled to the power plug via the changeover switch in the first stateor the second state.
 8. The dust collector according to claim 7, whereinthe control power source is supplied power via the power plug and thechangeover switch independent of the power supplied to the dustcollection portion.
 9. The dust collector according to claim 6, whereinthe control power source includes an isolation transformer.
 10. The dustcollector according to claim 1, further comprising a power outletconfigured to receive the alternating-current power from thealternating-current power source, the power outlet being configured tosupply an alternating-current power to an external device, wherein thechangeover switch is coupled to the power outlet.
 11. The dust collectoraccording to claim 10, wherein the power outlet is electrically coupledto the power plug via the changeover switch in the first state or thesecond state.